The present invention relates gnerally to case packing machines, and more particularly to case packing machines where containers or other articles are transferred from an infeed conveyor to a case loading station.
Case packing machines for packing bottles or other containers into compartmentalized and noncompartmentalized cartons are widely used. Typically, such case packing machines utilize a continuously-running infeed conveyor belt to advance the containers in side by side rows to a dead plate adjacent a loading station. From the dead plate, the containers are moved to the loading station. Once the containers are moved to the loading station, they are aligned in a grid structure, which commonly employs actuatable bars which support the containers immediately before being loaded in a case. Upon actuation of the bars, the containers are dropped as a group into the case positioned below the loading station.
Packing of the containers into the grid structure from the dead plate is usually done intermittently. Consequently, those containers positioned on the dead plate during the time between intermittent loadings of the grid structure experience line pressure exerted by upstream containers still being advanced by the continuously-running infeed conveyor belt. The line pressure, when exerted on the containers positioned on the dead plate, can result in undesirable distortion, jamming, or even breakage of containers, especially odd-shaped, flexible, or slender profiled containers, making difficult the correct loading of the grid structure with the containers. Such creates special problems in that, today, shapes of containers are consistently being changed from the traditional round shape to triangular, rectangular, square, or oblong shapes and the like. Further, because of the increased use of plastic containers, the problem with containers compressing and deforming under the influence of upstream conveyor line pressure is increased.
One particular problem arises with the packing of flask or oval-shaped containers. With these type of containers, there is a tendency for the narrow sides of adjacent containers to overlap each other or "shingle", causing hte containers to become disordered. Because the containers to be packed are typically transported through walled lanes for maintaining the containers in rows, if the disordered configuration of "shingling" occurs, the containers may force outwardly on the walled lanes, causing the walls of the lanes to bulge such that containers transported in adjacent lanes are impeded to the point that they may no longer move. In such a situation, the lanes adjacent the dead plate area will become jammed such that the packing machine must be shut down in order for the situation to be alleviated.
Various case packing machines have been patented for transferring containers from an infeed conveyor to a case loading station. U.S. Pat. No. 3,273,723, granted to Anderson, discloses a packing machine having a bottle gripping head for gripping the upper portions of bottles on a conveyor and for transporting the bottles from the conveyor to a packing case. U.S. Pat. No. 3,327,450, granted to Carter, discloses a case packer having a pick-up head equipped with vacuum cups for transporting containers from a conveyor to a case packing station. U.S. Pat. No. 3,965,650, granted to Nussbaum, discloses a case packing machine having a removable drop plate assembly disposed beneath containers transported by a conveyor such that after the conveyors have advanced to a pre-packing staging position, the drop plate assembly is shifted for allowing the containers to fall into an underlying carton. And, U.S. Pat. No. 4,457,121, granted to Johnson, et al., discloses a bottle packing machine having a rotating grid structure which receives containers from a conveyor and transfers them downwardly into a case.
More pertinent to the present invention are several patented case packing machines having structures which pick up articles through the use of inflatable members, the inflatable members then being used to transport the articles. For example, U.S. Pat. No. 3,826,382, granted to Zappia, entitled, "Case Packer" discloses a case packer having a gripper assembly which includes diaphragms. The diaphragms are inflatable for gripping bottles to the gripper assembly. A conveyor is provided for bringing the bottles to the gripper assembly for accumulation in the gripper assembly. When the gripper assembly has been filled with bottles by the conveyor, the diaphragms are inflated to grip the bottles to a carriage, and the carriage is either reciprocated or oscillated for loading the bottles upright or upside-down, respectively, in packing cases upon deflation of the diaphragms.
U.S. Pat. No. 4,048,783 granted to Raudat et al., entitled, "Case Loader With Invert Grid and Pushdown Feature", discloses a device which includes a grid for receiving articles as the articles are fed across a dead plate by an infeed conveyor. The grid structure includes rails which support the articles advanced therein. The grid structure also includes inflatable lane dividing elements having bladders for expanding outwardly to retain the articles with the grid structure during subsequent rotation of the grid structure. This allows for the loading of the bottles in an inverted position into a case. Before the grid structure is inverted, it is retracted slightly, from a position as shown in FIG. 2B of the patent to a position as shown in FIG. 3B, to allow clearance between itself and upstream portions of the machine.
U.S. Pat. No. 3,834,117, granted to Gift, entitled, "Lane Defining Apparatus for Handling Articles in Columns", discloses a device having wall means which include bladders for expanding outwardly to retain articles to a grid structure as the grid structure is inverted for depositing the articles upside-down in the packing case. Line pressure generated by upstream articles on the infeed conveyor moves the articles into lanes of the grid structure.
Other types of container transport devices include inflatable gripping assemblies. One such assembly is disclosed in U.S. Pat. No. 2,784,997, granted to Baumann. Another such assembly is the Schaberger Pneumagrip manufactured by Pneumatic Scale Corporation of Quincy, Massachusetts. However, these devices are for depalletizing containers, not for transferring containers from an infeed conveyor to a case loading station.
Further, applicant has knowledge of a machine whereby an inflatable device is used to force articles traveling single-file on a conveyor against a fixed surface for stopping and starting the flow of the articles by the conveyor. Applicants consider the present invention fully patentable over this inflatable device and the patented devices cited above.